All Phenotypes Pcdh15<av-2J> MGI Mouse

hearing/vestibular/ear phenotype ( J:106625 )

N	• normal endocochlear potential • histochemistry of the organ of Corti shows the centrosomes in the normal position • cytocauds are not observed

abnormal cochlear hair cell morphology ( J:106625 )

• diminished amounts of actin in the stereocilia and cuticular plate, the outer perimeter of hair cells has a distorted shape

• the inner hair cells are more severely affected than the outer hair cells

abnormal cochlear hair cell stereociliary bundle morphology ( J:106625 )

abnormal inner hair cell stereociliary bundle morphology ( J:106625 )

• stereocilia bundles on inner hair cells can be nearly invisible or tall and disorganized

short cochlear hair cell stereocilia ( J:106625 )

• short and distorted stereocilia bundles

abnormal cochlear outer hair cell morphology ( J:106625 )

• outer hair cells are extremely distorted, a more severe phenotype than in av-J homozygotes

abnormal outer hair cell stereociliary bundle morphology ( J:106625 )

abnormal orientation of outer hair cell stereociliary bundles ( J:106625 )

• some outer hair cells have stereocilia bundles that are rotated 90 degrees away from normal orientation

cochlear hair cell degeneration ( J:106625 )

• near complete loss of inner and outer hair cells by 60 days of age

abnormal organ of Corti supporting cell morphology ( J:106625 )

• diminished actin in the supporting cells, particularly the pillar and Hensen cells

abnormal Hensen cell morphology ( J:106625 )

abnormal pillar cell morphology ( J:106625 )

increased or absent threshold for auditory brainstem response ( J:106625 )

• as early as 9 days of age there is no ABR response even at 20 kHz

abnormal vestibular system physiology ( J:148677 )

• styryl pyridinium dye AM1-43 staining of the utricular maculae shows much less fluorescence and fewer stain-filled hair cells than in controls indicative of diminished transduction by these hair cells

absent linear vestibular evoked potential ( J:116914 , J:148677 )

• variable penetrance; in 2 of 4 mice tesed, VESPs are absent at the maximum stimulus intensity used (J:116914)

• in remaining two mice tesed, responses are measurable, but abnormal (J:116914)

• homozygotes that failed to orient in water had no linear vestibular evoked potential (J:148677)

impaired righting response ( J:106625 )

ataxia ( J:106625 )

• between 2 and 6 weeks of age homozygotes have an ataxic gait, tend to fall over, and have difficulty righting themselves, although this neurologic phenotype diminishes as they reach adulthood. This phenotype is not found in the av-J or av-3J homozygotes, indicating a greater severity of phenotype in the av-2J mutant

impaired balance ( J:106625 )

impaired swimming ( J:106625 , J:116914 , J:148677 )

• mice exhibit poor swimming ability; mice can not maneuver in the water and can not remain at the surface (J:116914)

circling ( J:106625 , J:116914 )